This invention relates to an intercommunicating apparatus for a duplex system, in particular, to an intercommunicating apparatus and an intercommunicating method capable of detecting an abnormality of intercommunicating information between processor boards in a duplex processor apparatus.
In a duplex processor apparatus (or system) in which two processor units are used as mates (i.e. active and standby processor systems), the processor units intercommunicate various kinds of information signals between them to make possible to be switched one to another upon occurrence of a failure in the active processor system.
Presently, the processor boards on which processor units are mounted individually have intercommunicating portions connected to each other with cables or buses and forming an intercommunicating apparatus for transmitting and receiving the information signals.
The information signals must be transmitted and received between the intercommunicating portions without fail. Thus, the existing intercommunicating apparatus is designed so as to detect cable disconnection for the cables between the intercommunicating portions.
However, the existing intercommunicating apparatus has a problem that it can not deal with a failure except for the cable disconnections.